Board for mounting display element

Abstract

A board usually resembling a PCB or a PWB mounts a display element, whose appearance in a viewing direction is controlled by the sense of magnetization of a core which extends through a bore in the board. A conducting coil formed on the surface of said board is located so that current in said coil will magnetize the core.

We claim: 
     
       1. A board, means for mounting a display element thereon,   wherein said display element displays differing appearances in a viewing direction in response to the direction of magnetization of a magnetizable core,   means for causing said core to extend through a bore in said board,   a conducting coil formed on a surface on said board shaped and located to magnetize said core in a sense determined by the direction of current flow in said coil.   
     
     
       2. A board, a bore therethrough,   a thin conducting layer on said board providing a current path,   said path being shaped to magnetize a core located in said bore in a sense dependant on the directions of flow of current in said path,   a display element mounted on said board adapted to display one appearance or another in a viewing direction in response to the magnetization of said core.   
     
     
       3. A board as claimed in claim 1 wherein said path is located on a surface of said board and forms at least one turn about said bore. 
     
     
       4. A board as claimed in claim 2 wherein said path is shaped to provide at least one turn about said bore. 
     
     
       5. A board as claimed in claim 1 wherein said core is made of magnetic material. 
     
     
       6. A board as claimed in claim 2 wherein said core is made of magnetic material. 
     
     
       7. A board as claimed in claim 3 which is made up of a plurality of sub layers wherein said coil is formed of at least two spirals which are located on different layers of said board, adjacent said bore and wherein said at least two spirals are connected in series so that the current in both coils magnetizes said core in the same sense. 
     
     
       8. A board as claimed in claim 4 wherein said board is made up of a plurality of layers and wherein said path is shaped to provide at least two spirals located on different layers of said board, adjacent said bore and wherein said at least two spirals are connected in series so that the current in both coils magnetizes said core in the same sense. 
     
     
       9. A board as claimed in claim 1 wherein said display element has two pins and there is provided a coil corresponding to each pin said coils being connected in series and shaped so that the magnetization of each pin is opposite to the other for either direction of current flow. 
     
     
       10. A board as claimed in claim 1 wherein said display element has two pins received in spaced bores and there is provided a path corresponding to each pin, said paths being connected in series and shaped so that the magnetization of each pin is opposite to the other for either direction of current flow.